A linear regulator is also referred to as a series regulator. A linear regulator can be used to convert an unstable input voltage into an adjustable direct output voltage so as to provide a power source to another system. A linear regulator has a simple structure, less static power consumption, and a small output voltage ripple etc. As a result, the linear regulator is generally used for the intra-chip power source management of a chip in a consumer mobile electronic device.
FIG. 1 is a schematic structural diagram of a linear regulator in the related art. The linear regulator includes: a bias module 1, a reference voltage module 2, an error amplifier 3, a power transistor 4, and a sampling resistor network 5.
An input voltage VIN of the linear regulator is input into the bias module 1, the reference voltage module 2, and the power transistor 4, respectively. The bias module 1 provides a current bias and a voltage bias to the reference voltage module 2 and the error amplifier 3 for a normal operation of the reference voltage module 2 and the error amplifier 3. The reference voltage module 2 generates a reference voltage VREF with a low temperature drift for the error amplifier 3. The error amplifier 3 amplifies an error between VREF and a feedback voltage VFB that is obtained by sampling an output voltage VO by a sampling resistor network 5, so as to regulate a gate voltage of the power transistor 4 according to an error amplification result and to stabilize an output of the output voltage VO.
With fast development of technologies in the Internet of Things, people have higher requirements on mobile consumer electronic devices. When a system of an electronic device is in a sleeping standby state, power consumption of intra-chip power source management of an electronic device chip should be as low as possible, so as to achieve a longer device operation time and a relatively long electronic device standby time. However, a linear regulator in the related art may be difficult to satisfy a requirement that a static current is in the range of hundreds of nanoamperes or even dozens of nanoamperes when the electronic device is in a standby state. In addition, the sampling resistor network 5 in the linear regulator of related art occupies a relatively large chip area, which is disadvantageous to the development of miniaturizing an electronic device.